Usually, in the prior art, hitch balls for "gooseneck" type trailers are permanently bolted or welded to the bed of a hauling truck, such as a pick-up truck. The hitch ball projects above the surface of the truck bed and creates a tripping hazard, and often damages cargo such as feed or fertilizer sacks. Additionally, up to one-third or more of the hauling space of the truck can be lost due to the hitch ball extending permanently above the surface of the truck bed. All of these objections to permanently installed non-retractable hitch balls are completely overcome by the present invention.
While some retractable hitch mechanisms are known in the prior art, these in general possess no actuating means other than the hands of the user to move the ball from an extended to a retracted position. The present invention completely eliminates such awkward practices by providing a retractable hitch ball and ball actuating mechanism which is remotely controlled hydraulically from the cab of the truck. Hydraulic lines are extended from the truck's power steering pump to a two-way hydraulic cylinder contained in the housing of the hitch ball extending and retracting mechanism secured under the truck bed.
Another significant advantage possessed by the invention is that the remotely controlled retractable hitch ball renders the operation of hitching and unhitching a gooseneck trailer much easier, safer and quicker. The retractable ball element is simply raised to its active use position and the truck is backed under the tongue of the trailer. A few turns of the dolly wheel crank completes the hook-up. To unhitch the trailer, it is merely necessary to set the dolly wheel at trailer-towing height, retract the hitch ball and move the truck forwardly. The invention virtually eliminates all cranking of the dolly wheel while under load.
A further important feature and object of the invention is to provide a retractable hitch ball arrangement of the type mentioned wherein the ball element can support a substantial load without damaging or overstressing any part of the ball extending and retracting mechanism. When the hitch ball is extended to the load bearing position, the weight borne by the ball is supported solidly by an elevating block or wedge element so that the hydraulic cylinder does not bear the load through internal fluid pressure. The arrangement is such that the hitch ball is securely locked in the extended use position and is biased to return automatically to its retracted position when the ball elevating block connected with the rod of the hydraulic cylinder is retracted. There is no strain on the hydraulic cylinder when the hitch ball is up or down.
Other objects and advantages of the invention will become apparent to those skilled in the art during the course of the following description.